Contact Lens Safety for the Correction of Refractive Error in Healthy Eyes.

ABSTRACT: Contact lenses are a safe and effective method for correction of refractive error and worn by an estimated 45 million Americans. Because of the widespread availability and commercial popularity of contact lenses, it is not well appreciated by the public that contact lenses are U.S. Food and Drug Administration (FDA)-regulated medical devices. Contact lenses are marketed in numerous hard and soft materials that have been improved over decades, worn in daily or extended wear, and replaced in range of schedules from daily to yearly or longer. Lens materials and wear and care regimens have impact on the risks of contact lens-related corneal inflammatory events and microbial keratitis. This article reviews contact lens safety, with specific focus on the correction of refractive error in healthy eyes.

Bilateral Pseudomonas aeruginosa Keratitis in 7 Patients.

PURPOSE: To report 7 patients (14 eyes) with bilateral Pseudomonas aeruginosa keratitis (PAK). METHODS: Case records of patients with bilateral PAK were reviewed at a single academic medical center from April 2009 to December 2020. RESULTS: Seven patients aged 29 to 94 years presented with bilateral P. aeruginosa corneal ulcers. All patients were soft contact lens wearers except one elderly patient with a complex ocular history. Three patients wore specialty contact lens, including one cosmetic contact lens wearer, one multifocal contact lens wearer, and one extended-wear contact lens wearer. The remaining three patients were not overnight contact lens wearer but regularly showered in contact lens or used tap water for contact lens case cleaning. All patients presented with asymmetric disease, with visual acuity ranging from 20/20 to light perception. Ulcers were located centrally in 5 eyes (35.7%), diffusely over the entire cornea in 5 eyes (35.7%), temporally in 2 eyes (14.2%), and nasally in 1 eye (7.14%), and in 1 eye (8.3%), the ulcer location was not recorded. Corneal thinning was noted in 7 eyes (50%). Hypopyon was also noted in 7 eyes (50%). Two patients required procedures because of progressive stromal necrosis. All other patients were treated nonsurgically, with antibiotic drops, which resulted in ulcer resolution. Final visual acuity on last recorded follow-up ranged from 20/20 to no light perception. CONCLUSIONS: This is the largest case series of bilateral PAK, which occurred primarily in contact lens wearer. This case series reiterates the risk of contact lens infection related to poor hygiene.

Antibacterial and physical properties of a novel sonochemical-assisted Zn-CuO contact lens nanocoating.

PURPOSE: This work examined the antibacterial and physical effects of a novel Zn-CuO nanocoating applied on a silicone hydrogel contact lens. METHODS: Zn-CuO coating of PureVision balafilcon-A soft contact lenses (Bausch&Lomb, Rochester, NY) was performed by sonochemical deposition using a high-intensity ultrasonic horn. Non-coated PureVision lenses served as a control in all experiments. Adhesion assays for P. aerueginosa and S. epidermidis to the coated lenses were performed to identify the minimal coating concentration which still possessed antibacterial activity. Lens water content, oxygen transfer light transfer, leaching, and electron microscopy studies were performed using this concentration. RESULTS: Coated lenses showed 3-5 log reductions in adhesion of both species. The lowest tested coating concentration of 0.02 wt% led to a log reduction of 3.25 ± 1.25 of P. aeruginosa CFU/lens (P = 0.007) and a log reduction of 4.37 ± 0.75 of S. epidermidis (p = 0.0007). Using this coating concentration, water content (36%, 33.6%), oxygen transfer (87.22 ± 10.96, 92.18 ± 2.38, × 10-11(cm2/s)(mlO2)/(ml × mmHg)), p = 0.12), and light transfer properties did not differ significantly between the coated and the control contact lenses. In the range of 380-780 nm wavelength, the coated lenses transmitted 96.47 ± 1.52% while the control lenses transmitted 97.36 ± 1.35%. The corresponding values for the range of 300-380 nm wavelength were 79.343 ± 8.754 and 80.169 ± 1.35. Leaching studies for 0.5 mM coated lenses have demonstrated the excellent stability of the coating with the release of only 0.005% of the coating after 1 week of exposure to the test solution. CONCLUSION: Sonochemical-assisted nanocoating of contact lenses showed significant and consistent antibacterial activity while preserving the basic properties of a silicone hydrogel contact lens.

Anterior Corneal Curvature and Aberration Changes After Scleral Lens Wear in Keratoconus Patients With and Without Ring Segments.

OBJECTIVE: To evaluate changes in the anterior corneal curvature and aberrometry after scleral contact lens wear in keratoconus (KC) subjects with and without intracorneal ring segments (ICRS). METHODS: Twenty-six subjects diagnosed with keratoconus were selected to participate in the study. Subjects were divided into 2 groups, those with ICRS (KC-ICRS group) and those without ICRS (KC group). Subjects were instructed to wear 16.5-mm scleral lenses for 8 hours. Topographic and aberrometric parameters were evaluated before lens wear and immediately after lens removal. Anterior corneal curvature was evaluated at corneal diameters of 2, 4, 6, and 8 mm, and corneal aberrations were measured at 4-, 6-, and 8-mm pupil diameters. RESULTS: The mean age of subjects was 36.95±8.95 years. In KC group, there was a statistically significant flattening of the central corneal curvature, from 6.98 to 7.09 mm (P<0.05). No changes were found in the central corneal curvature in the KC-ICRS group. The KC group showed anterior corneal curvature flattening, mainly in the nasal quadrant. The KC-ICRS group showed flattening primarily in the inferior hemisphere. In the KC group, spherical aberration for 6-mm pupil increased significantly. In the KC-ICRS group, changes in aberrations were significant for high-order root mean square at 4- and 6-mm pupil diameters (P<0.05), for oblique astigmatism for 4 mm and 6 mm, and for vertical coma for 4-mm pupil (P<0.05). CONCLUSION: Short-term scleral lens wear showed flattening of the anterior corneal surface in all subjects. In the KC group, the flattening was more pronounced in the nasal quadrant while changes were more pronounced inferiorly in KC-ICRS group.

Comparative Analysis of Adverse Events From a Series of Proof-of-Principle Extended Wear Studies.

AIM: A series of proof-of-principle extended wear (EW) contact lens studies were conducted to assess what effect different interventions had on adverse events (AEs). Comparative analysis of AEs across studies was conducted to determine whether some interventions were more effective at reducing inflammatory AEs. METHOD: Multiple logistic regression analysis of AEs from 30-day EW studies each with a different intervention including (1) nightly replacement (NR) of lenses, (2) morning replacement (MR) of lenses, (3) instillation of prophylactic antibiotic drops (AB) each morning/evening, (4) daily lens cleaning (LC) each morning. All studies conducted at the same site using same lens type (lotrafilcon A) and EW schedule. RESULTS: Comparison of the different interventions to the individual control groups showed no difference in significant corneal infiltrative event (CIE) or mechanical events. Replacing lenses nightly, during an EW schedule, had the highest incidence of significant CIEs (4.9% [NR] vs. 2.5% [MR] vs. 1.8% [AB] vs. 0% [LC]); however, adjusted logistic regression analysis of the combined control data compared with the individual interventions showed no difference in significant CIEs (P=0.086) or mechanical AEs (P=0.140). CONCLUSIONS: Replacing lenses each night seemed to be inferior compared with the other interventions of replacing lenses each morning, daily lens cleaning, and daily antibiotic drop instillation during EW. The results of the collective studies and additional analysis suggest that overnight wear of contact lenses seems to create an adverse environment that remains, despite the various interventions intended to improve this adverse environment.

Successfully Improving Visual Acuity in Keratitis-Ichthyosis-Deafness Syndrome Utilizing Gas-Permeable Lenses: A Case Report.

There is currently no well-defined guideline for treatment and management of patients with keratitis-ichthyosis-deafness (KID) syndrome, and most patients will face disabling vision loss due to corneal neovascularization and cicatrization. We offer this case as an example of how we can improve visual acuity (VA) and quality of life even in advanced cases of corneal neovascularization. We showcase the use of gas-permeable (GP) contact lenses to provide useful, functional VA in a patient with long-standing visual impairment secondary to corneal neovascularization and irregularity due to KID syndrome. The patient's VA improved from 20/200 both eyes (OU) to 20/40 OU with successful fitting of GP lenses, which additionally relieved the patient's otherwise intractable monocular diplopia.

Comparison of Extended Depth-of-Focus Prototype Contact Lenses With the 1-Day ACUVUE MOIST MULTIFOCAL After One Week of Wear.

OBJECTIVES: To compare visual performance of extended depth-of-focus (EDOF) prototypes with a new, center-near, commercial, multifocal contact lens. METHODS: Presbyopic participants (n=57) wore 1-Day ACUVUE MOIST MULTIFOCAL (1DAMM) and an EDOF prototype for one week in a double-masked, prospective, cross-over, randomized clinical trial. Manufacturers' guide was used to select the first pair of lens to be fit based on subjective distance refraction and near addition. After one week, high- and low-contrast visual acuities were measured at distance (6 m), intermediate (70 cm) and near (50 and 40 cm), and stereopsis at 40 cm. Subjective performance was assessed on a 1 to 10 numeric rating scale for vision clarity and lack of ghosting at distance, intermediate and near, vision stability, haloes at night time, overall vision satisfaction, and ocular comfort. Linear mixed models were used for analysis and the level of significance was set at 5%. RESULTS: 1DAMM was not significantly different from EDOF for high- or low-contrast visual acuity at any distance, or for stereopsis. Subjectively, EDOF was significantly better than 1DAMM for vision clarity at intermediate (P=0.033) and near (P<0.001), overall lack of ghosting (P=0.012), vision stability (P=0.004), and overall vision satisfaction (P=0.005). For all other subjective variables, there were no differences between EDOF and 1DAMM (P>0.05). CONCLUSIONS: EDOF prototype lenses offer improvements over the newly marketed 1DAMM lenses for several subjective variables.

The Nonsurgical Management of Orbital Dystopia Using Refractive Lenses and Prosthetic Shells.

Surgical rehabilitation of orbital dystopia can be challenging. The authors demonstrate the effective use of spectacle lenses to visually correct misalignments of the globe and the orbit. Presented is a retrospective review of 4 patients undergoing aesthetic rehabilitation through use of spectacle lenses and in a number patients a cosmetic shell.Two patients with neurofibromatosis presented with inferior dystopia of the globe and orbit. A base-down prismatic lens applied to the spectacles in conjunction with a prosthetic shell successfully visually corrected the facial asymmetry and improved patients' aesthetic appearance. One patient with a history of traumatic retinal detachment, who did not want any surgical intervention, a "plus" (hypermetropic) lens was used to magnify the perceived image of an enophthalmic and phthisical globe, to enhance appearance and improve symmetry. In the fourth patient, with Goldenhar syndrome, the appearance of a hypotropia and concurrent esotropia was successfully treated with a Fresnel prism and a prosthetic shell.This case series illustrates the successful role of various refractive lenses often in conjunction with prosthetic shells in patients with reduced vision and orbital dystopia to improve facial symmetry. This conservative treatment is especially useful when surgery is not a desired or not considered a suitable option for the patient.

Mucin Balls Influence Corneal Infiltrative Events.

PURPOSE: To determine whether mucin ball (MB) formation is protective against corneal infiltrative events (CIEs) as previously reported. METHODS: Two hundred eighty-two eligible participants were enrolled at three sites in the USA. Participants began a 1-month continuous wear run-in period with high modulus lotrafilcon A lenses to assess their ability to form MBs (phase 1). Subsequently, they were stratified by this characteristic and randomized to balafilcon A or comfilcon A lenses for 7-day extended wear and followed for 1 year (phase 2). MB formation in each phase was defined as repeated presence of any MBs on a person level. Multivariable Cox proportional hazards regression was used to model the probability of a CIE as a function of MB formation in each phase and other covariates. RESULTS: Of the 282 participants who entered phase 1, 218 of them entered the phase 2 randomized trial during which 33 CIEs occurred. Overall, 74%, 61%, and 79% of participants repeatedly produced MBs in lotrafilcon A, balafilcon A, and comfilcon A lenses, respectively. Early repeated MB presence in phase 1 with lotrafilcon A lenses significantly increased the rate of CIEs in phase 2 (12-month follow-up) by 466% (HR 4.66, 95% confidence interval 1.10-19.79, P = .0372). Repeated, longer-term MB presence during wear of balafilcon A or comfilcon A in phase 2 did not significantly reduce the incidence of CIEs; however, it significantly decreased the rate of CIEs by 62% (hazard ratio (HR) 0.380, 95% confidence interval 0.145-0.998, P = .0494). CONCLUSIONS: The overarching hypothesis that MB formation is protective against CIEs throughout extended wear was not supported. Although a protective effect of longer-term MB presence on rate of CIEs was detected, early-onset MB formation substantially increased the hazard for CIE in subsequent wear with different lens types.

Improvement of Subjective Symptoms and Eye Complications When Changing From 2-Week Frequent Replacement to Daily Disposable Contact Lenses in a Subscriber Membership System.

PURPOSE: Subjective symptoms and other eye complications were assessed and retrospectively compared in patients belonging to a proprietary membership system who switched from 2-week frequent replacement (2WFR) wear to daily disposable (DD) lens use. METHODS: Questionnaire responses were completed by all patients for a 5-year interval between October 2008 and September 2013 from 83 wearers in three Japanese clinics (59 female and 24 male; average age: 33.4±10.9 years). Complications were recorded for each patient at times of reexamination. RESULTS: Over the 5-year observation period, the 83 patients wore lenses for more than 26 months. The average duration of use of 2WFR lenses was 14.5±2.7 days/lens (n=83) and subsequently 1.03±0.12 days/lens (n=83) for DD lenses. Compliance with the duration of use was consistently good as monitored by requests for lens resupply in both wearing modalities. The subjective complaint of dryness tended to consistently show improvement by the change to DD wear: 18.1% vs. 30.1% (P=0.10, Fisher exact test). Among eye complications noted in each group, the occurrence of superficial punctate keratitis (SPK) was significantly decreased in DD wear: 9.6% vs. 26.5% (P=0.008, Fisher exact test). The main reasons given by patients for changing to DD wear were (1) "DD lens wear was more hygienic" (78.6%) and (2) "DD lens use is more convenient for travel/business trips" (64.3%). Comments after the switch in wear were (1) "easy and convenient" (95.7%) and (2) "I don't have to worry about expiration dates" on solutions (57.1%). Overall, 95.7% of wearers making the change answered as "satisfied" and "mostly satisfied." CONCLUSIONS: In the subscription membership program, which provided free lens replacement and/or reexamination, individual compliance with duration of wear in 2WFR wear cycles was good; however, these patients switching to DD wear tended to have improvement in their subjective complaints of dryness and objectively demonstrated a significant reduction of SPK at follow-up examinations.

Effect of Daily Contact Lens Cleaning on Ocular Adverse Events during Extended Wear.

PURPOSE: The purpose of the study was to assess what effect daily cleaning of contact lenses with a multipurpose disinfection solution (MPDS), during 30 nights extended wear, would have on contact lens-related adverse events. METHODS: This was a prospective, open-label, randomized, controlled, parallel-group, 3-month clinical study in which 193 participants were dispensed with lotrafilcon A silicone hydrogel lenses for a 30-day extended-wear schedule and with lenses replaced monthly. Participants were randomized to a control or test group. Test subjects were required to remove lenses daily after waking, clean them with the MPDS, and reinsert the lenses. Control subjects wore lenses without removal for 30 days extended wear. Handling-related lens contamination was assessed at the baseline visit. RESULTS: There was no significant difference between the test and control groups for the incidence of significant corneal infiltrative events (1.3 vs. 4.9%, p = 0.368), total corneal infiltrative events (2.6 vs. 4.9%, p = 0.682), or mechanical events (1.3 vs. 2.5%, p = 1.00). The test group had greater corneal staining (p < 0.047) and fewer mucin balls (p = 0.033). Handling-related lens contamination (unworn lenses) resulted in isolation of Gram-positive bacteria from 92.5% of test lenses compared with 87.5% of control lenses (p = 0.712). Gram-negative bacteria were isolated from 5% of test subjects compared with 2.5% of control subjects (p = 1.00). Fungus was isolated from 2.5% of subjects in both the test and control groups (p = 1.00). CONCLUSIONS: The intervention of daily morning cleaning of the lens surface with an MPDS during extended wear did not significantly influence the incidence of adverse events.

Contact Lens Use in Patients With Boston Keratoprosthesis Type 1: Fitting, Management, and Complications.

The Boston type 1 keratoprosthesis (KPro) is the most commonly used artificial cornea worldwide. Long-term bandage contact lenses are the standard of care for patients with these devices. The goal of bandage contact lenses is to maintain hydration and to protect the corneal tissue that surrounds the anterior plate of the keratoprosthesis which is vulnerable to desiccation, epithelial breakdown, dellen formation, and corneal melt. Contact lenses can also improve comfort, correct refractive errors, and improve the cosmesis of patients with artificial corneas. However, the continuous use of contact lenses places these patients at risk for complications such as lens loss, lens deposits, chronic conjunctivitis, and infection. In addition, obtaining an adequate fit in a patient with a compromised ocular surface and history of multiple surgeries including glaucoma drainage devices can present a challenge. This review discusses the types of contact lenses used, special fitting considerations, and common complications in patients with previous KPro surgery.

Effect of antibiotic drops on adverse events during extended lens wear.

PURPOSE: Overnight lens wear is associated with increased lens contamination and risk of developing a corneal infiltrate or infectious event. Antibacterial lenses have been proposed as a potential strategy for reducing lens contamination. A proof-of-principle study was conducted to investigate what effect control of potential pathogens, through the use of antibiotic eye drops, would have on the incidence of corneal infiltrative events (CIEs) and on the ocular microbiota and lens contamination. METHODS: This is a prospective, open-label, controlled, parallel-group, 1-month clinical study in which 241 subjects were dispensed with lotrafilcon A silicone hydrogel lenses for 30 days of continuous wear. Subjects were randomized into either test (moxifloxacin 0.5%) or control (rewetting solution) group. One drop was instilled into each eye on waking and before sleeping, while lenses were on-eye. Follow-ups were conducted after one night and 1 month. Lid margin swabs were taken at baseline and at 1 month and worn lenses were aseptically collected at 1 month. RESULTS: The incidence of CIEs was not significantly different between the test (2.6%) and control (3.9%) groups (p = 0.72). Microorganism levels from the test group swabs were significantly lower than those from the control group (p = 0.001). Gram-positive bacteria were less frequently recovered from lower lid swabs from the test group (39.6% vs. 66.0% [p < 0.001], test vs. control, respectively) or from contact lens samples (1.9% vs. 10.5% [p = 0.015], test vs. control, respectively), but there was no difference in gram-negative bacteria (GNB). Corneal infiltrative events were associated with higher levels of lens contamination (p = 0.014) and contamination of lenses with GNB (CIE: 7.3% vs. 0.6% [p = 0.029], GNB contamination vs. no GNB contamination, respectively). DISCUSSION: Twice-daily antibiotic instillation during continuous wear of lenses did not significantly influence the rate of inflammatory events. Corneal infiltrative events were associated with higher levels of lens contamination in general and with contamination by GNB specifically.

Microbial keratitis secondary to unintended poor compliance with scleral gas-permeable contact lenses.

PURPOSE: To report a case of neurotrophic keratitis in which scleral contact lenses improved vision from 20/100 to 20/20, however, due to poor lens care, an incident of microbial keratitis developed. METHODS: A 64-year-old man with an ocular history of neurotrophic keratitis secondary to herpes simplex in each eye was successfully fit with scleral lenses. He subsequently developed microbial keratitis due to a number of risk factors. RESULTS: The lesion was culture negative, yet was very responsive to treatment with moxifloxacin. The lesion fully healed, and the patient did not suffer additional vision loss. CONCLUSIONS: This case demonstrates the ability of scleral lenses to correct visual impairments secondary to poor epithelial integrity and illustrates the importance of the practitioner providing detailed lens care instruction.

Clinical performance of a new hybrid contact lens for keratoconus.

OBJECTIVES: To compare the clinical performance of the Clearkone hybrid contact lens for the treatment of keratoconus against the habitual contact lens of the patients. METHODS: A total of 33 eyes from 18 patients were fitted with the Clearkone. High- and low-contrast visual acuity (HCVA and LCVA), central corneal thickness (CCT), and contrast sensitivity acuity (CSF) were recorded with habitual lenses (prestudy visit) and after 1 week, 15 days, and 1 month of wear of prescribed Clearkone. Subjective vision and comfort were rated using visual analogue scales (VAS). RESULTS: Three patients discontinued the study, one because of diffuse corneal staining after 1 day of use and the other two because of extreme discomfort. The rest of the patients completed the 1-month study. High contrast visual acuity and LCVA (logMAR) improved significantly from 0.16 ± 0.12 and 0.44 ± 0.22, respectively, with the patient's habitual contact lenses to -0.006 ± 0.058 and 0.23 ± 0.13 after 1 day wearing Clearkone, remaining significant during all follow-up visits (P<0.001; repeated measures analysis of variance [RM-ANOVA]). There were no statistically significant differences in the mean CCT. The improvement of CSF was statistically significant with hybrid contact lenses prescribed compared with the patient's habitual contact lenses (P<0.001; RM-ANOVA test). Improvement in VAS score, with prescribed Clearkone, was statistically significant for comfort (P=0.043; RM-ANOVA test), but not for the subjective vision (P=0.759; RM-ANOVA test). CONCLUSIONS: Clearkone provides an improvement in visual acuity, contrast sensitivity, and subjective comfort in patients with keratoconus when compared with other contact lens options. However, clinicians must get specific training to fit the lens and be aware of potential adverse events.

Contact lens fitting and long-term management for the Boston keratoprosthesis.

OBJECTIVES: To examine the types of contact lenses used as bandage lenses in the postoperative management of patients with Boston type 1 keratoprosthesis (K-Pro). We examined the lens parameters, the number of trial lenses used to achieve successful fit, and lens replacement schedule. The strategies to achieving a successful fit in these complex patients are reviewed. METHODS: This was a single-center, retrospective chart review of patients who had undergone implantation of the Boston keratoprosthesis in 1 or more eyes from January 2006 to December 2011. Patients included male and female subjects aged 18 years or older who had been fit with bandage contact lenses as part of their postoperative management. RESULTS: Twenty-two eyes of 15 patients met the criteria for this review. The age range was 30 to 90 years. There were eight men and seven women. The average number of lenses to achieve a successful fit varied from 1 to 8, with an average of 2.22 trial lenses used per patient. By 6 months after the surgery, 12 K-Pro eyes showed visual acuity of 20/200 or better, with 7 of those eyes attaining better than 20/80 best-corrected Snellen distance acuity. CONCLUSIONS: Our results show that it is often necessary to use custom contact lenses for K-Pro patients. Management of poor tear film quality, protein deposition, inflammation, lens replacement schedule, and antibiotic resistance are related considerations.

Risk factors for contact lens-induced papillary conjunctivitis associated with silicone hydrogel contact lens wear.

BACKGROUND: Contact lens-induced papillary conjunctivitis (CLPC) continues to be a major cause of dropout during extended wear of contact lenses. This retrospective study explores risk factors for the development of CLPC during extended wear of silicone hydrogel lenses. METHODS: Data from 205 subjects enrolled in the Longitudinal Analysis of Silicone Hydrogel Contact Lens study wearing lotrafilcon A silicone hydrogel lenses for up to 30 days of continuous wear were used to determine risk factors for CLPC in this secondary analysis of the main cohort. The main covariates of interest included substantial lens-associated bacterial bioburden and topographically determined lens base curve-to-cornea fitting relationships. Additional covariates of interest included history of adverse events, time of year, race, education level, gender, and other subject demographics. Statistical analyses included univariate logistic regression to assess the impact of potential risk factors on the binary CLPC outcome and Cox proportional hazards regression to describe the impact of those factors on time-to-CLPC diagnosis. RESULTS: Across 12 months of follow-up, 52 subjects (25%) experienced CLPC. No associations were found between the CLPC development and the presence of bacterial bioburden, lens-to-cornea fitting relationships, history of adverse events, gender, or race. Contact lens-induced papillary conjunctivitis development followed the same seasonal trends as the local peaks in environmental allergens. CONCLUSIONS: Lens fit and biodeposits, in the form of lens-associated bacterial bioburden, were not associated with the development of CLPC during extended wear with lotrafilcon A silicone hydrogel lenses.

Contact lens care solutions: a pilot study of ethnic differences in clinical signs and symptoms.

OBJECTIVES: To determine whether Asian and white subjects differ in clinical signs or subjective symptoms in response to the use of different biguanide-preserved contact lens care solutions. METHODS: Forty-two subjects (15 Asian and 27 white) wearing lotrafilcon B silicone hydrogel contact lenses used a preservative-free lens care solution bilaterally for 2 weeks, then used two biguanide-preserved solutions (solution 1: ReNu MPS; solution 2: AQuify MPS) contralaterally in randomly assigned eyes for 4 weeks. Comprehensive ocular surface examinations were performed and symptomatology questionnaires were administered every 2 weeks. Investigators were masked as to solution assignment during examinations, whereas subjects were not to avoid potential difficulties in compliance with the protocol. RESULTS: With solution 1, most Asian and white subjects had grade 2 or greater corneal staining after 2 weeks (67% and 59%, respectively) and 4 weeks (60% and 67%, respectively). With solution 2, grade 2 or greater corneal staining occurred in 40% of Asians after 2 weeks and in 13% after 4 weeks, but in only 4% of whites after 2 weeks and 0% after 4 weeks. Whites reported significantly better average comfort (P=0.046) and less dryness (P<0.001) than did Asians. CONCLUSIONS: Asians and whites differ in both ocular response to the use of contact lens care solutions and in reporting subjective symptoms. Racial and ethnic differences should be considered when evaluating and treating contact lens patients in a clinical setting.

Quantification of individual proteins in silicone hydrogel contact lens deposits.

PURPOSE: The aim of this study was to quantify specific proteins deposited on daily wear silicone hydrogel lenses used in combination with multipurpose disinfecting solutions (MPDSs) by applying multiple-reaction-monitoring mass spectrometry (MRM-MS). METHODS: Balafilcon A or senofilcon A contact lenses used with different MPDSs on a daily wear schedule were collected. Each worn lens was extracted and then digested with trypsin. MRM-MS was applied to quantify the amounts of lysozyme, lactoferrin, lipocalin-1, proline-rich protein-4, and keratin-1 in the extracts. RESULTS: The amount of protein extracted from the contact lenses was affected by the individual wearers, lens material, and type of care system used. Higher amounts of proteins were extracted from lenses after wear when they were used with an MPDS containing polyhexamethylene biguanide (PHMB) and poloxamer 407 compared with MPDSs containing polyquaternium-1 (PQ-1)/alexidine dihydrochloride with Tetronic 904 or PQ-1/ PHMB with poloxamine and sulfobetaine (p < 0.05). There was a correlation between the amount of lipocalin-1 or keratin-1 extracted from lenses and symptoms of ocular dryness. CONCLUSIONS: The MRM-MS technique is a promising approach that could be used to reveal associations of individual proteins deposited on lenses with performance of contact lenses during wear.

The future of silicone hydrogels.

Significant advances during the past decade in silicone hydrogel lenses have made them the primary mode for new contact lens wear. Their dominance in the market place is driven largely by the elimination of structural and physiological changes induced by contact lens-induced hypoxia, as exemplified especially by the reduction in limbal redness. However, end-of-day dryness and discomfort still drives many to discontinue lens wear. Evidence also indicates that the rate of serious adverse events, such as microbial keratitis, have not been impacted with the use of silicone hydrogel lenses. Moreover, there are additional challenges relating to 'corneal staining' and corneal infiltrates associated with the incompatibility of lens care product with contact lens polymers. On the other hand, technological advances enabled by the high oxygen platform present opportunities for expanding the use of contact lenses in areas that have exhibited limited uptake in the past such as astigmatism, presbyopia, and importantly myopia control. The challenges and opportunities facing the field will be discussed.